STELLENBOSCH, South Africa — Oscar Pistorius' case will return to court next month after his lawyers said Tuesday they will challenge a judge's decision to allow prosecutors to appeal the Olympic runner's negligent killing conviction.

Prosecutors want Pistorius convicted of the more serious crime of murder for shooting girlfriend Reeva Steenkamp in 2013 and were granted permission in December to take the case to South Africa's Supreme Court of Appeal.

Fighting back, Pistorius lawyers' said in their brief statement Tuesday that they have applied to argue against Judge Thokozile Masipa's ruling to allow prosecutors to appeal.

Their application will be heard in court on March 13, Pistorius' lawyers said.

Masipa presided over Pistorius' seven-month murder trial last year and found the double-amputee athlete guilty of culpable homicide for shooting Steenkamp multiple times through a closed toilet door in his home on Valentine's Day. She ruled Pistorius did not intend to kill Steenkamp and acquitted him of murder, but found he acted negligently when he fired four times through the door from close range with his 9 mm pistol.

Pistorius testified he mistook Steenkamp for a dangerous nighttime intruder.

Masipa also allowed prosecutors — who argued Pistorius committed premeditated murder after a fight with his girlfriend— to then appeal against her culpable homicide verdict.

If the Supreme Court of Appeal finds that Pistorius should have been found guilty of murder, as prosecutors contend, he faces a minimum sentence of 15 years in prison. A date has not been set for any Supreme Court appeal by the prosecution.

Pistorius was sentenced to five years in prison and is being held at a prison in the South African capital, Pretoria. He could be eligible to be moved to house arrest in August, when he may be able to serve the remainder of his sentence at his uncle's home.

The Olympian and multiple Paralympic champion turned 28 in November while in prison.